Battery management system, soh-based battery control method, vehicle, device

Abstract

The application provides a battery management system, a battery control method based on SOH, a vehicle and equipment, relates to the technical field of batteries, and the battery management system is in communication connection with a vehicle-mounted display device; the battery management system is configured to: acquire a first SOH value and a second SOH value estimated for a battery pack, and a third SOH value actually measured for the battery pack; the first SOH value is obtained based on cycle use data of the battery pack, the second SOH value is obtained based on natural attenuation data of the battery pack, a display SOH value is calculated according to the first SOH value and the second SOH value, transient working condition interference is avoided, a display instruction is generated based on the display SOH value, and the display SOH value is smooth and continuous; a real SOH value is determined based on the third SOH value and the display SOH value, the real state of the battery is accurately captured, and the real aging level of the battery is restored. The application can realize the combination of battery safety control and user display experience.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery management system, a battery control method based on SOH, a vehicle, and equipment. Background Technology

[0002] In recent years, with the rapid development of the new energy vehicle industry and the continuous increase in the market share of new energy vehicles, users have become increasingly concerned about the lifespan of power batteries. Battery State of Health (SOH) has become an important parameter for measuring battery aging and assessing remaining usability. However, in actual battery pack use, due to factors such as differences in cell heat dissipation conditions and inconsistent cell aging, the voltage of individual cells under the same charge and discharge conditions often shows significant deviations. Existing SOH calculation schemes are prone to abnormal phenomena such as jumps and sharp drops in calculation results under these circumstances. The obtained SOH values ​​cannot accurately reflect the actual health status of the battery, failing to meet display requirements and thus affecting users' accurate judgment of battery lifespan. Therefore, a SOH management solution that can overcome these problems is urgently needed. Summary of the Invention

[0003] This application provides a battery management system, a battery control method based on State of Health (SOH), a vehicle, and equipment to solve one or more of the above-mentioned technical problems.

[0004] In a first aspect, embodiments of this application provide a battery management system, which is communicatively connected to an in-vehicle display device. The battery management system is configured to: acquire an estimated first SOH value and a second SOH value for a battery pack, and a measured third SOH value for the battery pack; the first SOH value is obtained based on the cyclic usage data of the battery pack, and the second SOH value is obtained based on the natural degradation data of the battery pack; calculate a display SOH value based on the first SOH value and the second SOH value, and generate a display instruction based on the display SOH value; the display instruction is used to instruct the in-vehicle display device to display the display SOH value; determine a true SOH value based on the third SOH value and the display SOH value; generate a warning instruction based on the true SOH value; and the warning instruction is used to issue a warning based on the aging state of the battery pack.

[0005] Secondly, embodiments of this application provide a battery pack including the battery management system described in any of the above claims.

[0006] Thirdly, embodiments of this application provide an electric vehicle, including the aforementioned battery pack and in-vehicle display device.

[0007] Fourthly, embodiments of this application provide a battery control method based on State of Health (SOH), applied to the battery management system described in any of the above claims. The method includes: obtaining an estimated first SOH value and a second SOH value for a battery pack, and a measured third SOH value for the battery pack; the first SOH value is obtained based on the cyclic usage data of the battery pack, and the second SOH value is obtained based on the natural degradation data of the battery pack; calculating a display SOH value based on the first SOH value and the second SOH value, and generating a display command based on the display SOH value; the display command is used to instruct the vehicle-mounted display device to display the display SOH value; determining a true SOH value based on the third SOH value and the display SOH value, and generating a warning command based on the true SOH value; the warning command is used to issue a warning based on the aging state of the battery pack.

[0008] Fourthly, embodiments of this application provide an electronic device, including a memory, a processor, and a computer program stored in the memory, wherein the processor, when executing the computer program, implements the method described in any of the above-mentioned embodiments.

[0009] Compared with related technologies, this application has the following advantages:

[0010] This application provides a battery management system, a battery control method based on State of Health (SOH), a vehicle, and equipment. The battery management system is communicatively connected to an in-vehicle display device. The battery management system is configured to: acquire an estimated first SOH value and a second SOH value for the battery pack, and a measured third SOH value for the battery pack; the first SOH value is obtained based on the battery pack's cycle usage data, thereby reflecting the degree of aging and degradation of the battery accumulated under cycle conditions; the second SOH value is obtained based on the battery pack's natural degradation data, thereby reflecting the degree of natural aging and degradation of the battery over time; then, based on the first SOH value and the second SOH value, a display SOH value is calculated and based on... The dual-slow variable aging trend coupling calculation avoids instantaneous operating condition interference. A display command is generated based on the displayed SOH value, instructing the in-vehicle display device to display the displayed SOH value. The displayed SOH value is smooth and continuous, without jumps, drops, or abrupt changes. By determining the true SOH value based on the third SOH value and the displayed SOH value, the true state of the battery can be accurately captured without excessive smoothing or passivation, thus better reflecting the real-time aging level of the battery. A warning command is generated based on the true SOH value, providing early warnings based on the aging state of the battery pack. This avoids the problem of mismatch between the control strategy and the actual aging level of the battery due to the smoothing lag of the displayed SOH value. This embodiment of the application achieves a balance between battery safety management and user display experience.

[0011] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0012] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments according to this application and should not be construed as limiting the scope of this application.

[0013] Figure 1 A structural block diagram of a battery management system provided in an embodiment of this application is shown;

[0014] Figure 2 A flowchart of a battery control method based on SOH provided in an embodiment of this application is shown;

[0015] Figure 3 A structural block diagram of a battery pack provided in an embodiment of this application is shown;

[0016] Figure 4 A block diagram of an electronic device used to implement embodiments of this application is shown. Detailed Implementation

[0017] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the concept or scope of this application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0018] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies of the embodiments of this application are described below. The following relevant technologies are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and all of them fall within the protection scope of the embodiments of this application.

[0019] As the industry continues to raise the bar for the assessment standards of the health and safety status of power batteries, the battery management system (BMS) not only needs to have accurate underlying capacity calculation capabilities to accurately grasp the current real health status of the battery, but also needs to maintain stable and smooth health status data displayed and diagnosed externally, avoiding large jumps, in order to meet the requirements of relevant assessment standards for data consistency and user experience.

[0020] Based on this, this application provides a battery management system, a battery control method based on SOH, a vehicle, and equipment. By performing layered processing on the battery's actual health status and the health status displayed externally, it achieves ultimate safety control internally based on real and sensitive health status data, and outputs compliant, stable, and desensitized health status data externally, thereby balancing the safety of battery control with the compliance and stability of external data display.

[0021] The technical solution of this application and how it solves the aforementioned technical problems are described in detail below with specific embodiments. The listed specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0022] This application provides a battery management system. For example... Figure 1 The diagram shown is a structural block diagram of a battery management system according to an embodiment of this application. The battery management system 100 is communicatively connected to an in-vehicle display device 200; the battery management system is configured as follows:

[0023] The system acquires an estimated first SOH value and a second SOH value for the battery pack, as well as a measured third SOH value for the battery pack. The first SOH value is obtained based on the battery pack's cycle usage data, and the second SOH value is obtained based on the battery pack's natural degradation data. Based on the first and second SOH values, a display SOH value is calculated, and a display command is generated based on the display SOH value. The display command instructs the in-vehicle display device to display the display SOH value. The system determines the true SOH value based on the third SOH value and the display SOH value. A warning command is generated based on the true SOH value. The warning command is used to issue a warning based on the aging state of the battery pack.

[0024] In this embodiment, the first SOH value is a health status estimate obtained based on the battery pack's cyclic usage data, used to characterize the degree of capacity decay caused by continuous charge-discharge cycles. The second SOH value is a health status estimate obtained based on the battery pack's natural decay data, used to characterize the degree of capacity decay that occurs naturally due to factors such as storage time, storage temperature, and storage SOC, also known as calendar aging health. Both the first and second SOH values ​​are health status values ​​estimated based on battery operating data, rather than values ​​obtained through direct measurement. The displayed SOH value is a health status value calculated based on the first and second SOH values ​​and used for external display. Since the first and second SOH values ​​are estimates for two independent dimensions—cyclic aging and natural decay—their numerical changes are relatively continuous and gradual. Therefore, the displayed SOH value calculated from these two values ​​exhibits a relatively smooth and stable change characteristic, making it suitable as health status data for external display and diagnostic output.

[0025] The third SOH value is a health status value obtained from actual measurements of the battery pack, used to characterize the battery's current, instantaneous capacity state. Unlike the first and second SOH values, which are based on estimations, the third SOH value is based on actual measurement data of the battery pack, reflecting instantaneous capacity changes and eliminating estimation lag. The true SOH value is a health status value determined by combining the third SOH value and the displayed SOH value, used as a basis for controlling the battery pack. The true SOH value integrates the estimation trend reflected in the displayed SOH value and the actual instantaneous state reflected in the third SOH value, providing a more accurate reflection of the battery's current true aging level.

[0026] In this embodiment, a first SOH value and a second SOH value are obtained based on cyclic usage data and natural decay data, respectively, and a displayed SOH value is calculated accordingly. A display command is generated based on the displayed SOH value. The display command instructs the in-vehicle display device to display the displayed SOH value, ensuring that the displayed SOH value exhibits a relatively smooth and stable trend, meeting the stability requirements for externally displayed health status data. By combining a third SOH value obtained from actual measurements with the displayed SOH value to determine the true SOH value, the true SOH value can more accurately reflect the current true capacity state of the battery. By generating a warning command based on the true SOH value, the warning command is used to issue a warning based on the aging state of the battery pack, rather than directly using the displayed SOH value for warning control. This allows the battery pack control strategy to better align with the actual state of the battery, while simultaneously controlling the in-vehicle display device to display the displayed SOH value, thus meeting both battery safety management and external data display requirements.

[0027] This application provides a battery management system that is communicatively connected to an in-vehicle display device. The battery management system is configured to: acquire an estimated first SOH value and a second SOH value for the battery pack, and a measured third SOH value for the battery pack; the first SOH value is obtained based on the battery pack's cycle usage data, reflecting the degree of aging and degradation accumulated by the battery under cyclic operating conditions; the second SOH value is obtained based on the battery pack's natural degradation data, reflecting the degree of natural aging and degradation of the battery over time; subsequently, based on the first SOH value and the second SOH value, a display SOH value is calculated, based on a dual-slow variable aging trend coupling... By combining calculations and avoiding instantaneous operating condition interference, a display command is generated based on the displayed SOH value. This display command instructs the in-vehicle display device to display the displayed SOH value. The displayed SOH value is smooth and continuous, without jumps, drops, or abrupt changes. By determining the true SOH value based on the third SOH value and the displayed SOH value, the true state of the battery can be accurately captured without excessive smoothing or passivation processing, thus better reflecting the real-time aging level of the battery. A warning command is generated based on the true SOH value. This warning command is used to provide early warnings based on the aging state of the battery pack, avoiding the problem of mismatch between the control strategy and the actual aging level of the battery due to the smoothing lag of the displayed SOH value. This embodiment of the application can achieve a balance between battery safety management and user display experience.

[0028] In one possible implementation, generating a warning command based on the actual SOH value can be performed as follows: if the actual SOH value is greater than a first SOH threshold, no warning command needs to be generated; if the actual SOH value is less than or equal to the first SOH threshold and greater than a second SOH threshold, a warning command is generated and executed using the in-vehicle display device; if the actual SOH value is less than or equal to a third SOH threshold, a warning command is generated, executed using the in-vehicle display device, and a warning message is sent to the target device using the in-vehicle terminal device; wherein the first SOH threshold is greater than the second SOH threshold, and the second SOH threshold is greater than the third SOH threshold.

[0029] In this possible implementation, since the true SOH value can accurately reflect the current actual aging level of the battery pack, this application divides the aging state of the battery pack into different level ranges by pre-setting multiple SOH thresholds, and configures corresponding early warning processing methods for different level ranges to achieve hierarchical early warning management of the aging state of the battery pack.

[0030] When the actual SOH value is greater than the first SOH threshold, it indicates that the current capacity level of the battery pack is still within the normal range and there are no obvious signs of aging and degradation. At this time, the battery management system does not need to generate a warning command, the vehicle maintains normal use, and no additional prompts are given to the user to avoid unnecessary disturbance.

[0031] When the actual SOH value is less than or equal to the first SOH threshold and greater than the second SOH threshold, it indicates that the battery pack has experienced a certain degree of aging and degradation, but has not yet reached the severity required for further treatment. At this time, the battery management system generates a warning command and executes the warning command using the in-vehicle display device. That is, it presents corresponding prompt information to the user through in-vehicle display devices such as the instrument panel and central control screen, reminding the user to pay attention to the current health status of the battery. For example, it suggests that the user pay attention to driving habits and pay attention to changes in battery status in a timely manner. The warning at this stage is mainly a local prompt within the vehicle and does not involve sending information to external devices.

[0032] When the actual SOH value is less than or equal to the third SOH threshold, it indicates that the battery pack is aging significantly and requires greater attention. In this case, the battery management system not only generates a warning command and executes it using the in-vehicle display device to alert the user inside the vehicle, but also further uses the in-vehicle terminal device to send warning information to the target device, synchronizing the abnormal aging status of the battery pack to relevant external devices or platforms for timely follow-up measures such as after-sales maintenance and remote monitoring. In one embodiment, the target device may include at least one of the following: the user's mobile terminal, the automaker's cloud server, and / or an after-sales service platform.

[0033] Since the first SOH threshold is greater than the second SOH threshold, and the second SOH threshold is greater than the third SOH threshold, the above three real SOH value ranges correspond to different states of battery pack aging from light to severe in descending order of value. Based on this, this application configures three processing methods from light to severe for battery packs with different aging degrees: "no warning required", "in-vehicle local warning", and "in-vehicle warning and synchronized external target device", realizing hierarchical management that matches the warning measures with the actual severity of battery pack aging.

[0034] In this possible implementation, by comparing the actual SOH value with multiple preset thresholds, different aging state levels are classified, and corresponding warning and handling measures are taken for different levels. This avoids a "one-size-fits-all" single warning mechanism, allowing the triggering and handling of warnings to be more precisely matched to the actual aging severity of the battery pack. When the battery pack aging is mild, no warning is generated; when the aging is moderate, a notification is provided in the vehicle via the in-vehicle display device. This ensures that users are aware of the battery status in a timely manner while avoiding excessive interference from frequent or unnecessary warning messages. When the battery pack aging reaches a severe level, in addition to in-vehicle notifications, the warning information is simultaneously sent to the target device via the in-vehicle terminal device. This allows automakers, after-sales service providers, and others to be aware of the abnormal aging status of the battery pack in a timely manner, facilitating timely intervention and reducing the risk of safety accidents caused by battery aging, thereby improving the safety management level of the battery pack throughout its entire life cycle.

[0035] In one possible implementation, obtaining the measured third SOH value of the battery pack can be performed by the following steps: integrating the current of the battery pack from the first time point to the second time point in ampere-hours to obtain a first capacity value; determining a second capacity value based on the equivalent capacity of the SOC range corresponding to the rated capacity of the battery pack; and using the ratio of the first capacity value to the second capacity value as the third SOH value.

[0036] In this possible implementation, the current of the battery pack during the period from the first time point to the second time point is integrated in ampere-hours to obtain a first capacity value. The first time point and the second time point are two characteristic time points with clear physical significance during the actual operation of the battery pack. By integrating the current flowing through the battery pack during this period in ampere-hours, the amount of charge actually released or stored by the battery pack during this period is obtained as the first capacity value. This value reflects the measured capacity of the battery pack during the period from the first time point to the second time point. Based on the equivalent capacity of the SOC range corresponding to the rated capacity of the battery pack, a second capacity value is determined. The second capacity value is an equivalent capacity value calculated based on the SOC corresponding to the first time point and the second time point, and is used to characterize the capacity level that the battery pack should theoretically have in the same SOC range under factory conditions, serving as a benchmark for comparison with the first capacity value.

[0037] The ratio of the first capacity value to the second capacity value is taken as the third SOH value. Since the first capacity value is obtained based on the integral of the measured current between the first and second time points, and the second capacity value is a theoretical benchmark value converted from the factory rated capacity of the battery pack, the ratio of the two reflects the degree to which the actual capacity of the battery pack is maintained relative to the factory capacity within the SOC range corresponding to the first and second time points. Therefore, the third SOH value obtained is a health status value calculated based on measured data, which can accurately reflect the current actual capacity status of the battery pack.

[0038] This application proposes a two-point capacity correction algorithm. It utilizes the full-charge endpoint of the vehicle's actual operation and the OCV (Open Circuit Voltage) steady-state point to accurately calculate the battery's current usable capacity, thus correcting the accuracy of the true SOH (State of Health). The calculation formula is: SOH c =C s / C a Among them, the first capacity value C s The actual capacity measured using the two-point method is obtained by integrating the AH (Area of ​​Charge) from the end of full charge to the steady-state OCV (Output Capacity) range during rest; the second capacity value C... a This represents the equivalent capacity within the SOC range corresponding to the battery's rated capacity. This method can accurately capture instantaneous capacity decay, voltage difference anomalies, and aging abrupt changes in the battery, without smooth passivation, ensuring that the true SOH perfectly matches the battery's current real state.

[0039] In this possible implementation, since the first capacity value is obtained based on the integral of the measured current within a specific range during the actual operation of the battery pack, rather than relying on model estimation, the third SOH value can accurately capture the instantaneous change in the battery pack capacity, objectively reflecting the actual capacity maintenance level of the battery pack within the corresponding range from the first moment to the second moment, providing an accurate measured data basis for determining the actual aging state of the battery pack by combining other health status estimates.

[0040] In one possible implementation, the first moment is the moment when the battery pack finishes full charging; the battery management system is configured to: detect the resting time and / or voltage change rate after the battery pack stops charging and discharging, and when the resting time reaches a preset time threshold and / or the voltage change rate is lower than a preset change rate threshold, the current moment is taken as the second moment.

[0041] In this possible implementation, the first moment is the end time of full charge of the battery pack, that is, the time point at which the battery pack completes one charging process and is determined to have reached a fully charged state. The end time of full charge can be determined by the battery pack's voltage, current, SOC and other parameters reaching preset full charge determination conditions during the charging process. For example, when the charging current drops to a preset cutoff current, or when the battery pack's SOC reaches a preset full charge threshold, the current moment is determined to be the end time of full charge.

[0042] The battery management system is configured to detect the resting time and / or voltage change rate of the battery pack after charging and discharging has stopped. When the resting time reaches a preset time threshold and / or the voltage change rate is lower than a preset change rate threshold, the current moment is taken as the second moment. Specifically, after charging and discharging stops, due to the polarization effect, the voltage of the battery pack does not immediately reach a stable state, but needs a period of self-recovery to stabilize. This process is usually characterized by the voltage gradually changing over time and eventually leveling off. To accurately determine whether the battery pack voltage has reached a stable state, the battery management system can determine this through at least one of the following two methods:

[0043] Firstly, the system detects the resting time of the battery pack since the moment charging and discharging stops. When the resting time reaches a preset time threshold, it is determined that the battery pack voltage has basically recovered and stabilized, and this current time is taken as the second time. The preset time threshold can be pre-set or calibrated based on the specific characteristics of the battery pack, temperature conditions, and other factors.

[0044] Secondly, the voltage change rate of the battery pack during the resting process is detected, that is, the amount of voltage change per unit time. When the voltage change rate is lower than a preset change rate threshold, the battery pack voltage is determined to have stabilized, and the current moment is taken as the second moment. Compared with simply judging based on a fixed resting time, the judgment method based on the voltage change rate can more directly reflect the actual recovery state of the battery pack voltage and has better adaptability under different conditions such as different temperatures and different aging levels.

[0045] In this embodiment of the application, the battery management system can also combine the two determination methods mentioned above. For example, it can simultaneously require the resting time to reach a preset time threshold and the voltage change rate to be lower than a preset change rate threshold before determining the current moment as the second moment, thereby further improving the accuracy of the determination of the second moment.

[0046] By defining the moment when the battery pack finishes charging as the first moment and the moment when the battery pack's voltage stabilizes as the second moment, both determined moments are state nodes that naturally occur during the actual operation of the battery pack and have clear physical meaning, rather than relying on a pre-set single voltage threshold as a trigger condition. Therefore, the first capacity value calculated based on the interval between the first and second moments can more accurately represent the true capacity state of the battery pack within that interval. This avoids the problem of inaccurate triggering times due to deviations in the voltage of individual cells within the battery pack, thus affecting the accuracy of capacity calculation. This provides a foundation for improving the calculation accuracy of the third SOH value.

[0047] In one possible implementation, the true SOH value is determined based on the third SOH value and the displayed SOH value, which can be done by the following steps: correcting the true SOH of the previous cycle using a preset correction coefficient and the third SOH value to obtain the true SOH value.

[0048] In this possible implementation, during the actual operation of the battery pack, the battery management system continuously monitors whether the first moment (i.e., the end of full charge) and the second moment (e.g., the moment when the resting voltage tends to stabilize) occur. When both the first and second moments are detected simultaneously, indicating that the triggering conditions have been met and a valid third SOH value can be obtained, the battery management system uses a preset correction coefficient to fuse the third SOH value with the actual SOH value determined in the previous cycle to obtain the actual SOH value for the current cycle. In other words, under the condition of triggering the two-point correction method for SOH, when it is detected that the vehicle has completed the resting phase after full charge and the OCV steady-state calibration, meeting the conditions for the two-point capacity calculation, a real-time capacity correction coefficient is introduced to iteratively update the actual SOH, avoiding numerical abrupt changes and conforming to the actual capacity decay state.

[0049] In this step, the update of the true SOH value is based on the third SOH value obtained from each actual measurement, and the correction range is controlled by a preset correction coefficient. This ensures that the true SOH value can respond promptly to instantaneous changes in the measured capacity of the battery pack, while avoiding unreasonable and drastic fluctuations in the true SOH value due to random errors in a single measurement. This balances the real-time performance and reliability of the data. On the other hand, by reasonably setting the value of the preset correction coefficient, the response speed and sensitivity of the true SOH value to the measured data can be flexibly adjusted according to actual application needs, improving the adaptability of this method in different application scenarios.

[0050] In one possible implementation, the true SOH value of the previous period is corrected using a preset correction coefficient and the third SOH value to obtain the true SOH value. This can be performed by the following steps: calculating the difference between a specified value and the preset correction coefficient; calculating the first product of the difference and the true SOH value of the previous period; calculating the second product of the preset correction coefficient and the third SOH value; and summing the first product and the second product to obtain the true SOH value.

[0051] In this possible implementation, the specified value is a preset baseline value, which in one implementation may be 1. Subtracting the specified value from the preset correction coefficient α yields a difference (1-α), which represents the weighting proportion retained by the true SOH value of the previous period in this correction process. Multiplying the difference (1-α) by the true SOH value of the previous period (SOH_true) yields a first product (1-α) × SOH_true, which reflects the contribution of the true SOH value of the previous period to the true SOH value of the current period. Multiplying the preset correction coefficient α by the third SOH value (SOH_c) yields a second product α × SOH_c, which reflects the contribution of the measured third SOH value to the true SOH value of the current period.

[0052] Summing the first product and the second product yields the true SOH value for this period. The specific calculation formula is as follows: SOH 真+1 =(1-α)×SOH 真 +α×SOH c Among them, SOH 真+1 The actual SOH value determined for this period, SOH 真 The actual SOH value determined in the previous period, SOH c The third SOH value obtained in this triggering process is α, which is a preset correction coefficient with a value greater than 0 and less than or equal to 1. It dynamically adapts to battery operating conditions, temperature, and aging level to ensure accurate correction without abrupt jumps. This iterative update mechanism can accurately capture the real-world states of the battery, such as instantaneous capacity drops, aging due to operating condition fluctuations, voltage differential degradation, and short-term attenuation, without excessive smoothing or passivation, thus maximizing the restoration of the battery's real-time aging level. This application's embodiments can be used for BMS internal AH capacity integration calibration, SOC correction, vehicle maximum charge / discharge power limitation, V2G high-power grid connection safety constraints, battery aging fault diagnosis, and high-voltage safety protection, ensuring vehicle control safety, etc.

[0053] In this embodiment, the true SOH value for the current cycle is obtained by weighted summation of the true SOH value of the previous cycle and the measured third SOH value according to a ratio determined by a preset correction coefficient, rather than directly replacing the true SOH value of the previous cycle with the current third SOH value. The preset correction coefficient α is used to control the weight of the measured third SOH value in the true SOH value of the current cycle: the larger the value of α, the higher the proportion of the measured data in the true SOH value of the current cycle, the closer the true SOH value is to the current third SOH value, and the more sensitive the response to instantaneous capacity changes of the battery pack; the smaller the value of α, the higher the proportion of the true SOH value of the previous cycle in the true SOH value of the current cycle, the smoother the change process of the true SOH value, and the less susceptible it is to the influence of random errors in single measured data. In one embodiment, the specific value of the preset correction coefficient α can be pre-calibrated and set according to the actual application scenario of the battery pack and the different requirements for the response speed and stability of the true SOH value, and this application does not limit it in this way.

[0054] The method of calculating the true SOH value by weighted summation has several advantages. First, it comprehensively considers both the true SOH value from the previous cycle and the third measured SOH value from the current test. This ensures that the true SOH value reflects the actual capacity status of the battery pack in a timely manner, while avoiding unreasonable and drastic fluctuations due to random errors or abnormal fluctuations in single-test data. This balances the real-time performance and stability of data updates. Second, by flexibly setting the preset correction coefficient α, the method can be tailored to the differentiated requirements of the sensitivity and stability of the true SOH value response in different application scenarios, thus improving the applicability and flexibility of the method provided in this application.

[0055] In one possible implementation, the true SOH value is determined based on the third SOH value and the displayed SOH value, which can be performed by taking the displayed SOH value as the true SOH value.

[0056] In this possible implementation, since the acquisition of the third SOH value depends on specific triggering conditions during the actual operation of the battery pack, namely the first moment (the end of full charging) and the second moment (e.g., the moment when the resting voltage tends to stabilize), if the battery pack does not experience a resting state that meets the second moment's judgment condition for a long time during actual use (e.g., the vehicle is frequently used for a long time, there is not a sufficient resting period, or the resting time / voltage change rate never reaches the preset judgment threshold), the battery management system will not be able to obtain a valid third SOH value within the specified period. In other words, under the condition that the two-point correction method for SOH is not triggered, without a valid full-charge resting calibration condition and without accurate capacity sampling data, the real SOH uses the SOH value displayed at the current period to ensure a consistent basic aging trend.

[0057] To address the above situation, the battery management system checks whether a second moment is detected within a specified time period. If it determines that a second moment is not detected within the specified time period, it indicates that there is no measured data basis for updating the third SOH value and thus correcting the true SOH value within this time period. In this case, the battery management system will display the SOH value directly as the true SOH value. The specified time period can be preset according to the actual application requirements of the battery pack. For example, it can be set to a fixed duration period, or the timing can start from the moment when the third SOH value was successfully obtained last time.

[0058] In this possible implementation, in the absence of effective measured data, the actual SOH value is replaced by the displayed SOH value calculated based on the fusion of the first and second SOH values. This ensures that during the period when the third SOH value cannot be obtained, the battery pack control strategy can still be based on a relatively reasonable and continuously updated health status value, avoiding the problem that the actual SOH value will remain unchanged and gradually become out of sync with the actual aging state of the battery due to the inability to trigger measured updates for a long time.

[0059] Determining the true SOH value through the above method ensures, on the one hand, that even when the battery pack fails to meet the third SOH value triggering condition for an extended period due to actual operating conditions, there is still a continuously updated set of true SOH values ​​for controlling the battery pack. This prevents the true SOH value from stagnating and losing its timeliness due to a lack of measured data. On the other hand, since the displayed SOH value itself is continuously estimated and updated based on the first and second SOH values, using it as a substitute source for the true SOH value during that period can still reflect the aging trend of the battery pack as it continuously changes with usage time and cyclic operating conditions. This ensures the rationality and continuity of the true SOH value during periods without measured correction, and improves the adaptability and robustness of the method provided in this application under various practical application scenarios.

[0060] In one possible implementation, the first time point is the time point corresponding to the first preset voltage threshold, and the second time point is the time point corresponding to the second preset voltage threshold.

[0061] In this possible implementation, as another optional implementation of the first and second time points, the battery management system can pre-set two different voltage thresholds, denoted as the first preset voltage threshold and the second preset voltage threshold, respectively. During the actual charging and discharging process of the battery pack, the battery management system monitors the voltage corresponding to the battery pack in real time. When the monitored voltage reaches the first preset voltage threshold, the corresponding time point is defined as the first time point; when the monitored voltage reaches the second preset voltage threshold, the corresponding time point is defined as the second time point. The first and second preset voltage thresholds can be pre-calibrated and set according to the specific voltage characteristics of the battery pack, the relationship between SOC and voltage, etc. For example, they can be set to the voltage values ​​corresponding to the lower and higher SOC ranges of the battery pack, respectively, so that there is a SOC range with a certain span between the first and second time points, thereby ensuring that the first capacity value obtained by ampere-hour integration based on this range has sufficient statistical significance.

[0062] In this possible implementation, by pre-setting a fixed voltage threshold as a trigger condition, the first and second moments can be obtained more conveniently and frequently during the normal charging and discharging process of the battery pack, without having to wait for the battery pack to reach a full charge or be idle for a long time. This allows the third SOH value to be obtained in more diverse usage scenarios, thereby increasing the update frequency of the third SOH value.

[0063] In one possible implementation, the displayed SOH value is calculated based on the first SOH value and the second SOH value, which can be achieved by summing the first SOH value and the second SOH value to obtain the displayed SOH value.

[0064] In this possible implementation, the first SOH value characterizes the capacity degradation of the battery pack due to cyclic use, and the second SOH value characterizes the capacity degradation of the battery pack due to natural storage. These two values ​​correspond to two independent degradation dimensions during the battery pack aging process, and the capacity degradation they reflect is additive. The first and second SOH values ​​can be expressed as the difference between 100% and the corresponding degradation amount. By directly summing the two values ​​and then subtracting a baseline value that is repeatedly included, the displayed SOH value, which comprehensively reflects the degradation contribution of both dimensions, can be obtained. The specific calculation method is as follows: SOH 显 =SOH a +SOH b -100%, of which SOH 显 To display the SOH value, SOH a The first SOH value, SOH b This is the second SOH value.

[0065] In this possible implementation, the first SOH value, i.e., the cycle life SOH a This is used to characterize the capacity decay of a battery due to continuous charge-discharge cycles. By statistically analyzing the cumulative equivalent charge-discharge cycles, the ratio of the actual usable capacity to the rated capacity of the battery at different cycle counts is obtained, reflecting the degree of aging and degradation of the battery accumulated under cyclic operating conditions. The calculation logic is as follows: based on the cumulative charge and discharge capacity, depth of discharge, and average temperature of the entire vehicle over a long period of time, the capacity retention rate corresponding to the current cycle aging is fitted to the value, which is used as the cycle life health (SOH). a The second SOH value, i.e., calendar lifetime SOH. b This technology characterizes the natural degradation of batteries due to static storage and aging over time. Based on different static storage days, temperature ranges, and SOC ranges, the battery capacity retention rate is obtained through periodic charge-discharge capacity calibration, reflecting the degree of natural aging and degradation of the battery over time. Calendar aging is a slow variable that does not fluctuate drastically with a single operating condition, and is the core basis for ensuring the smoothness of the displayed SOH. Both calendar life and cycle life are long-term, gradual changes that decrease slowly with battery aging; therefore, the displayed SOH value is smooth and continuous, without jumps, drops, or abrupt changes. The embodiments of this application can be used for user display on vehicle instrument panels, remote platform reporting, vehicle residual value display, and maintenance diagnostic output, effectively avoiding user anxiety and after-sales concerns caused by short-term SOH jumps, while meeting the compliance requirements of relevant regulations for smooth, de-identified, and stable output of external data.

[0066] It should be noted that the first SOH value and the second SOH value are each based on 100% as the health benchmark. If the two are added directly, the benchmark value will be counted twice. Therefore, the extra benchmark value needs to be subtracted from the summation so that the degradation corresponding to the first SOH value and the second SOH value can be correctly superimposed on the same benchmark. This allows the calculated displayed SOH value to truly and accurately reflect the overall capacity retention level of the battery pack under the combined effects of cycle aging and natural degradation.

[0067] In this possible implementation, by summing the first SOH value and the second SOH value in the manner described above to calculate and display the SOH value, the aging and degradation factors of the battery pack in two independent dimensions can be integrated into a unified health status value in a simple and easy-to-implement calculation method. Since both the first SOH value and the second SOH value are continuously and gradually updated based on the estimation model, the displayed SOH value calculated in this way also has the characteristics of continuous and smooth change, which is suitable as health status data for external display and diagnostic output, and meets the requirements of relevant assessment specifications for the stability of health status data.

[0068] In one possible implementation, obtaining the estimated first SOH value and second SOH value for the battery pack can be performed as follows: The cumulative charge / discharge capacity, depth of discharge, and average temperature of the battery pack are obtained; based on the cumulative charge / discharge capacity, depth of discharge, and average temperature, the capacity retention rate corresponding to the current cycle aging of the battery pack is fitted to obtain the first SOH value; the number of resting days, resting temperature range, and resting SOC range of the battery pack are obtained; based on the number of resting days, the resting temperature range, and the resting SOC range, the corresponding capacity retention rate is obtained through periodic charge / discharge capacity calibration to obtain the second SOH value.

[0069] In this possible implementation, the first SOH value is obtained as follows: The battery management system statistically analyzes the cumulative charge and discharge capacity of the battery pack during use, i.e., the cumulative value of the actual charge flowing through the battery pack during each charge and discharge cycle; simultaneously, it obtains the depth of discharge, i.e., the ratio of the actual discharge capacity to the rated capacity during a single or multiple discharge cycles; and it obtains the average temperature, i.e., the average operating temperature experienced by the battery pack within the statistical period. The cumulative charge and discharge capacity, depth of discharge, and average temperature are used as input parameters and substituted into a pre-established cyclic aging model for fitting calculation to obtain the capacity retention rate of the battery pack under the current cyclic operating conditions, which is then used as the first SOH value. Since the cumulative charge and discharge capacity, depth of discharge, and average temperature characterize the aging stress borne by the battery pack due to repeated charge and discharge cycles from different perspectives such as total charge and discharge volume, single depth of discharge, and temperature stress, fitting calculation of the above parameters can comprehensively reflect the degree of capacity decay of the battery pack caused by cyclic operating conditions.

[0070] The second SOH value is obtained as follows: The battery management system obtains the number of days the battery pack has been idle, i.e., the duration during which the battery pack is in a state of no charging or discharging; the idle temperature range, i.e., the temperature range during which the battery pack is idle; and the idle SOC range, i.e., the SOC range maintained by the battery pack during the idle period. Based on the above idle days, idle temperature range, and idle SOC range, the battery pack's capacity retention rate under different idle durations, different idle temperatures, and different idle SOC conditions is obtained by periodically calibrating the battery pack's charge and discharge capacity, and this is used as the second SOH value. Since even when the battery pack is in an idle state and has not undergone actual charge and discharge cycles, its internal chemical materials will still naturally age due to factors such as storage time, storage temperature, and storage SOC, the second SOH value is used to reflect the degree of capacity degradation caused by the above-mentioned natural storage factors.

[0071] In this possible implementation, on the one hand, by obtaining the first SOH value and the second SOH value for two independent aging dimensions—battery pack cyclic use condition and natural storage condition—the displayed SOH value calculated based on the fusion of the two values ​​can more comprehensively and accurately reflect the overall aging status of the battery pack, avoiding the one-sidedness of the assessment caused by considering only a single aging dimension. On the other hand, since both the first SOH value and the second SOH value are estimated based on fitting battery pack operating data and storage data, the data sources are easy to obtain and the calculation methods are relatively mature and reliable, making it easy to implement in actual vehicles and battery management systems.

[0072] Corresponding to the application scenario of the battery management system provided in the embodiments of this application, the embodiments of this application also provide a battery control method based on SOH. For example... Figure 2 The diagram shown is a flowchart of a battery control method based on SOH according to an embodiment of this application. The method may include:

[0073] Step S201: Obtain the estimated first SOH value and second SOH value of the battery pack, and the measured third SOH value of the battery pack; the first SOH value is obtained based on the cyclic usage data of the battery pack, and the second SOH value is obtained based on the natural degradation data of the battery pack;

[0074] Step S202: Calculate the display SOH value based on the first SOH value and the second SOH value, and generate a display instruction based on the display SOH value; the display instruction is used to instruct the vehicle display device to display the display SOH value;

[0075] Step S203: Determine the true SOH value based on the third SOH value and the displayed SOH value, and generate a warning instruction based on the true SOH value; the warning instruction is used to issue a warning based on the aging state of the battery pack.

[0076] This application provides a battery control method based on State of Health (SOH). The method obtains an estimated first SOH value and a second SOH value for the battery pack, as well as a measured third SOH value. The first SOH value is obtained based on the battery pack's cyclic usage data, reflecting the degree of aging and degradation accumulated by the battery under cyclic operating conditions. The second SOH value is obtained based on the battery pack's natural degradation data, reflecting the degree of natural aging and degradation of the battery over time. Then, based on the first and second SOH values, a displayed SOH value is calculated. This calculation is based on the coupled calculation of two slow variable aging trends, avoiding interference from instantaneous operating conditions. A display command is generated based on the displayed SOH value. This command instructs the in-vehicle display device to display the displayed SOH value. The displayed SOH value is smooth and continuous, without jumps, drops, or abrupt changes. By determining the true SOH value based on the third SOH value and the displayed SOH value, the actual battery state can be accurately captured without excessive smoothing or passivation, thus better reflecting the real-time aging level of the battery. A warning command is generated based on the true SOH value. This warning command is used to provide an alert based on the aging state of the battery pack, avoiding the problem of mismatch between the control strategy and the actual aging level of the battery due to the lag in smoothing the displayed SOH value. This embodiment of the application can achieve a balance between battery safety management and user display experience.

[0077] In one possible implementation, generating a warning instruction based on the actual SOH value includes: if the actual SOH value is greater than a first SOH threshold, no warning instruction needs to be generated; if the actual SOH value is less than or equal to the first SOH threshold and greater than a second SOH threshold, a warning instruction is generated and executed using the in-vehicle display device; if the actual SOH value is less than or equal to a third SOH threshold, a warning instruction is generated, executed using the in-vehicle display device, and a warning message is sent to the target device using the in-vehicle terminal device; wherein the first SOH threshold is greater than the second SOH threshold, and the second SOH threshold is greater than the third SOH threshold.

[0078] In one possible implementation, obtaining the measured third SOH value of the battery pack includes: integrating the current of the battery pack in ampere-hours from a first time point to a second time point to obtain a first capacity value; determining a second capacity value based on the equivalent capacity of the SOC range corresponding to the rated capacity of the battery pack; and using the ratio of the first capacity value to the second capacity value as the third SOH value.

[0079] In one possible implementation, the first moment is the moment when the battery pack finishes full charging; the method includes: detecting the resting time and / or voltage change rate after the battery pack stops charging and discharging, and when the resting time reaches a preset time threshold and / or the voltage change rate is lower than a preset change rate threshold, the current moment is taken as the second moment.

[0080] In one possible implementation, determining the true SOH value based on the third SOH value and the displayed SOH value includes: correcting the true SOH of the previous period using a preset correction coefficient and the third SOH value to obtain the true SOH value.

[0081] In one possible implementation, the true SOH value of the previous period is corrected using a preset correction coefficient and the third SOH value to obtain the true SOH value, including: calculating the difference between a specified value and the preset correction coefficient; calculating a first product of the difference and the true SOH value of the previous period; calculating a second product of the preset correction coefficient and the third SOH value; and summing the first product and the second product to obtain the true SOH value.

[0082] In one possible implementation, determining the true SOH value based on the third SOH value and the displayed SOH value includes: using the displayed SOH value as the true SOH value.

[0083] In one possible implementation, the first time point is the time point corresponding to a first preset voltage threshold, and the second time point is the time point corresponding to a second preset voltage threshold.

[0084] In one possible implementation, calculating the displayed SOH value based on the first SOH value and the second SOH value includes summing the first SOH value and the second SOH value to obtain the displayed SOH value.

[0085] In one possible implementation, obtaining the estimated first SOH value and second SOH value of the battery pack includes: obtaining the cumulative charge / discharge capacity, depth of discharge, and average temperature of the battery pack; fitting the capacity retention rate corresponding to the current cycle aging of the battery pack based on the cumulative charge / discharge capacity, the depth of discharge, and the average temperature to obtain the first SOH value; obtaining the number of resting days, the resting temperature range, and the resting SOC range of the battery pack; and obtaining the corresponding capacity retention rate through periodic charge / discharge capacity calibration based on the number of resting days, the resting temperature range, and the resting SOC range to obtain the second SOH value.

[0086] The functions of each step in the methods of this application embodiment can be found in the corresponding description in the above battery management system, and they have corresponding beneficial effects, which will not be repeated here.

[0087] This application also provides a battery pack including the battery management system described in any of the above embodiments. Figure 3 A structural schematic diagram of the battery pack 300 is shown.

[0088] This application also provides an electric vehicle, including the aforementioned battery pack and in-vehicle display device. In one possible implementation, the electric vehicle may include, but is not limited to: new energy passenger vehicles, commercial vehicles, power battery BMS systems, V2G (Vehicle-to-Grid) bidirectional charging and discharging vehicles, unmanned vehicles, vehicle-to-grid interactive energy storage systems, and new energy vehicle models equipped with charging and discharging capabilities.

[0089] Figure 4 This is a block diagram of an electronic device used to implement embodiments of this application. For example... Figure 4 As shown, the electronic device includes a memory 401 and a processor 402. The memory 401 stores a computer program that can run on the processor 402. When the processor 402 executes the computer program, it implements the method described in the above embodiments. The number of memories 401 and processors 402 can be one or more.

[0090] The electronic device also includes:

[0091] Communication interface 403 is used to communicate with external devices and perform data exchange and transmission.

[0092] If the memory 401, processor 402, and communication interface 403 are implemented independently, they can be interconnected via a bus to communicate with each other. This bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. This bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0093] Optionally, in a specific implementation, if the memory 401, processor 402, and communication interface 403 are integrated on a single chip, then the memory 401, processor 402, and communication interface 403 can communicate with each other through an internal interface.

[0094] This application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method provided in this application.

[0095] This application provides a computer program product, wherein the computer program product includes a computer program, which, when executed by a processor, implements the method provided in this application embodiment.

[0096] This application also provides a chip, which includes a processor for calling and executing instructions stored in a memory, causing a communication device with the chip installed to perform the method provided in this application.

[0097] This application also provides a chip, including: an input interface, an output interface, a processor, and a memory. The input interface, output interface, processor, and memory are connected through an internal connection path. The processor is used to execute code in the memory. When the code is executed, the processor is used to execute the method provided in the application embodiment.

[0098] It should be understood that the aforementioned processor can be a Central Processing Unit (CPU), or other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. General-purpose processors can be microprocessors or any conventional processor. It is worth noting that the processor can be a processor supporting Advanced Reduced Instruction Set Machines (ARM) architecture.

[0099] Further, optionally, the aforementioned memory may include read-only memory and random access memory. The memory may be volatile memory or non-volatile memory, or may include both. Non-volatile memory may include read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory may include random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available. Examples include Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Sync Link DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

[0100] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions according to this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0102] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0103] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process. Furthermore, the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functionality involved.

[0104] The logic and / or steps described in the flowchart or otherwise herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus or device (such as a computer-based system, a processor-included system or other system that can fetch and execute instructions from, an instruction execution system, apparatus or device).

[0105] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. All or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware, the program being stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiments.

[0106] It should be noted that the information and data involved in this application (including but not limited to data used for analysis, stored data, and displayed data) are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use, and processing of the relevant data must comply with the relevant laws, regulations, and standards of the relevant countries and regions, and corresponding operation portals are provided for users to choose to authorize or refuse.

[0107] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. This storage medium can be a read-only memory, a disk, or an optical disk, etc.

[0108] The above description is merely an exemplary embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope described in this application, and these should all be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A battery management system, characterized in that, The battery management system is communicatively connected to the in-vehicle display device; the battery management system is configured to: The first SOH value and the second SOH value of the battery pack are estimated, and the third SOH value of the battery pack is measured. The first SOH value is obtained based on the cyclic usage data of the battery pack, and the second SOH value is obtained based on the natural degradation data of the battery pack. Calculate the display SOH value based on the first SOH value and the second SOH value, and generate a display command based on the display SOH value; The display command is used to instruct the vehicle-mounted display device to display the displayed SOH value; The true SOH value is determined based on the third SOH value and the displayed SOH value, and an early warning command is generated based on the true SOH value. The warning command is used to issue a warning based on the aging status of the battery pack.

2. The battery management system according to claim 1, characterized in that, Based on the actual SOH value, an early warning instruction is generated, including: If the actual SOH value is greater than the first SOH threshold, there is no need to generate an early warning command; If the actual SOH value is less than or equal to the first SOH threshold and greater than the second SOH threshold, a warning command is generated and executed using the vehicle-mounted display device. If the actual SOH value is less than or equal to the third SOH threshold, a warning command is generated, the warning command is executed using the vehicle-mounted display device, and the warning information is sent to the target device using the vehicle-mounted terminal device; the first SOH threshold is greater than the second SOH threshold, and the second SOH threshold is greater than the third SOH threshold.

3. The battery management system according to claim 1, characterized in that, Obtaining the third SOH value of the battery pack as measured in practice includes: The first capacity value is obtained by integrating the current of the battery pack from the first time point to the second time point in ampere-hours. The second capacity value is determined based on the equivalent capacity of the SOC range corresponding to the rated capacity of the battery pack. The ratio of the first capacity value to the second capacity value is taken as the third SOH value.

4. The battery management system according to claim 3, characterized in that, The first moment is the time when the battery pack finishes full charging; the battery management system is configured as follows: The system detects the resting time and / or voltage change rate after the battery pack stops charging and discharging. When the resting time reaches a preset time threshold and / or the voltage change rate is lower than a preset change rate threshold, the current time is taken as the second time.

5. The battery management system according to claim 1, characterized in that, Determining the true SOH value based on the third SOH value and the displayed SOH value includes: The true SOH value of the previous period is obtained by correcting the true SOH value using a preset correction coefficient and the third SOH value.

6. The battery management system according to claim 5, characterized in that, The true SOH value of the previous period is obtained by correcting the true SOH value using a preset correction coefficient and the third SOH value, including: Calculate the difference between the specified value and the preset correction coefficient, and calculate the first product of the difference and the actual SOH value of the previous period; Calculate the second product of the preset correction coefficient and the third SOH value; The true SOH value is obtained by summing the first product and the second product.

7. The battery management system according to claim 1, characterized in that, Determining the true SOH value based on the third SOH value and the displayed SOH value includes: The displayed SOH value is taken as the actual SOH value.

8. The battery management system according to claim 3, characterized in that, The first time point is the time point corresponding to the first preset voltage threshold, and the second time point is the time point corresponding to the second preset voltage threshold.

9. The battery management system according to claim 1, characterized in that, The SOH value is calculated and displayed based on the first SOH value and the second SOH value, including: The first SOH value and the second SOH value are summed to obtain the displayed SOH value.

10. The battery management system according to claim 1, characterized in that, Obtain the estimated first and second SOH values ​​for the battery pack, including: The cumulative charge and discharge capacity, depth of discharge, and average temperature of the battery pack are obtained. Based on the cumulative charge and discharge capacity, the depth of discharge, and the average temperature, the capacity retention rate corresponding to the current cycle aging of the battery pack is fitted to obtain the first SOH value. The number of days the battery pack has been in a static state, the static temperature range, and the static SOC range are obtained. Based on the number of days the battery pack has been in a static state, the static temperature range, and the static SOC range, the corresponding capacity retention rate is obtained through periodic charge and discharge capacity calibration, and a second SOH value is obtained.

11. A battery pack, characterized in that, Includes the battery management system as described in any one of claims 1 to 10.

12. An electric vehicle, characterized in that, Includes the battery pack and vehicle display device as described in claim 11.

13. A battery control method based on SOH, characterized in that, The method, applied to the battery management system according to any one of claims 1 to 10, comprises: The first SOH value and the second SOH value of the battery pack are estimated, and the third SOH value of the battery pack is measured. The first SOH value is obtained based on the cyclic usage data of the battery pack, and the second SOH value is obtained based on the natural degradation data of the battery pack. Based on the first SOH value and the second SOH value, a display SOH value is calculated, and a display instruction is generated based on the display SOH value; the display instruction is used to instruct the vehicle display device to display the display SOH value; The true SOH value is determined based on the third SOH value and the displayed SOH value, and an early warning command is generated based on the true SOH value; the early warning command is used to issue an early warning based on the aging status of the battery pack.

14. An electronic device comprising a memory, a processor, and a computer program stored in the memory, wherein the processor, when executing the computer program, implements the method of claim 13.

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